The present invention is with respect to a mast foot structure for a sail board having a universal joint joining the mast with the sail board, there being an adjustable spring part for stopping injuries, more specially those otherwise caused by limbs of the boardsailor being squeezed between the mast and the top face of the deck.
Such a mast foot design has been put forward in an earlier invention of the applicant, see German Auslegeschrift specification 2,747,057. This known mast foot was designed as a safety connection using adjustable spring parts with the purpose of stopping injury, more specially injuries likely to be caused by the boardsailor's foot being squeezed between the mast and the top face of the deck of the board, the force which had to be overcome before the spring part let go of the mast being adjustable. On release of the spring part, acting as a sort of safety "binding" or connection the complete mast foot with the mast and the rig with it came out of a hole in the surf board hull so that the complete rig had to be joined to the board hull with a special leash. Although the general idea of this safety mast foot certainly gives the desired effect of stopping injury, because, in view of the fact that it may be adjusted by the boardsailor like a ski binding may be adjusted by a skier, it is possible for the danger of injury caused by limbs being squeezed to be completely put to an end, there is the shortcoming however that, more specially if the force to which the spring part is adjusted is low, it may well be that the rig be pulled out of the board hull without this being desired, more specially on pulling the rig out of the water, such as on sailing in choppy water or on surfing in breakers near the beach and in strong winds. Once the rig has been pulled out of the hull, the hull may no longer be maneuvred and there is a chance of the boardsailor falling from the board. This is specially undesired in competitions.